Mercury-vapor rectifier



Feb. 7,1939. J. G, w, MULDER n j 2,146,345

`MERCURY VAPOR RECTIFIER Filed Nov. 18, 1956 Patented Feb. 7, 1939 PATENT OFFICE Mintonltr-VAron.f nncfrlr'nin` Johannes Gjsbertus Wilhelm Mulder, Eindhoven,

Netherlands.' assigner toN. V. Philips Gloellampenfabrieken, Eindhoven, Netherlands Application Nnvember 1s, 1936,; serial No. 111,543

In Germany November-21, 1935 c isolams. wieso-21.5)

The `present invention, which forms a con`' tinuationn-part of my" copendngU. S. patent application Ser.` No. 67,155, filed March 4, 1936,

f relatestomercury-vapor rectiers and more par- 5i' ticularly to single-phase mercury-vapor rectifiers having metal-glass envelopes capable of being artificiallyl cooled.

In my'prior application I described a rectifier mhaving" a metal envelope portion containing a" lirrnercury` cathode and provided vwith a cooling" device in the form of a surrounding jacket, and

a glassenvelope portion exposed to the 4atmosphere. While with such a construction the metal portion `can be maintained at a practically unil'fform temperature of any desired degree, I have found* that thetemperature at different points of -the glass-` portion'greatly varies depending upon4 the position of these points with respect to rthe heat-radiating'parts of the tube. 20v" Such temperature differences 'of the glass porti'on had several disadvantages; for example, due

to the unduly` high local temperatures and dif` ference in temperatures, this portion may become damaged, and the mercury-vapor within the 25N rectier may condense upon an* excessively cold partof this portion. This `condensation may deleteriously affect the operation of the rectifier,

for instance by short-circuiting members under to maintain` the glass portions and metal portions. Thus,I either themetal. portion becomes too hot or theglass.. ,1U-portion surrounding. the anode becomes too cold.`

at widely diierent temperatures.

and as a result the mercury condensation adjacent the mercury supply will be insu'flicient,A but inthe neighborhood of the anode it` willy occur in avery undesired manner.

4&1 The object of my invention. is to eliminate the above disadvantages. and. for this purpose. I` provide means'to maintain the glass portionsj at a uniform temperature which is higher than that` of the metal portion and to such an extent that,

50wcondensatlon of mercury on the glass portions, aswell as on the tube parts within the same is avoided, and that practically the entire mercury1 condensation takes place in the coldest parts of theftube, i. e. iny parts adjacent the mercury More' particularly, I separately cool the metal envelope portion with a circulating liquid, and. surround. the glass envelope portion with a jacket forming a separate refrigerating chamber containing an insulating cooling substance that is 5*' liquid at the operating temperature of the rectier.

As the above-mentionedcooling of the hot glass portions may not suiice` for maintaining the de- ,l z sired" operating temperature, I prefer to adjal()` cently arrange the'cooling jackets for the `metal and glassportions and to separate same only by a member of' good heat conductivity. j

The `rectiers according'to the invention have the advantages that all parts of the glass portion can be maintained at such a temperature that there is no undesirable mercury condensation thereon or on the parts enclosed thereby. Furthermore, the glass portion is maintained at a uniform temperature throughout, whereby the possibility of cracking is considerably less than'if it were merely surrounded by the Iatmosphere.

Further advantages of my invention will appear as the description progresses.

In order that myr invention may be clearly understood. and readily carried into effect, I shall describe same more fully in connection with the accompanying drawing', in which the single gure is a sectionized side View of a single-phase mercury-vapor rectifier according to the invention.

The rectifier shown in the drawing has an envelope comprising a cup-shaped member I of metal, for instance chrome iron,V and an upper y portion 2 of glass hermetically'sealed thereto at 35 23. Within the bottom of portion I is a quantity offmercury 3 actingA as the cathode.

Hermetcally sealedV tothe upper end of portion 2 isla cup 4, for instance of ferrochrome, carrying on its upper surface a terminal I0. Secured 40 to the. lower surface of. cup 45 isa rod 8.0i conductive material having a` stepped lower end to whichn is screwed a main anode 5 ofvcylindrical shape and provided with a cylindrical slot 39. Surrounding` rod` 8 and insulatingly supported 45- therefrom by two insulating bushings, I2 and- I3 isa metal tube I4, which serves to screen the rod 8 from the discharge. A tube I5` of insulating material extends into a cavity in anode 5 `and screens the point of connection between bushing I3and` rod 4.

The glass 'portion 2' extends upwards into a tubular protuberance 4I), into whose upper end is hermetically sea-led `a plate 6, for instance of ferrochrome, carrying a terminal II'. Secured to plate 6 and extending downwardly is a rod 9 of conductive material carrying on its lower end a cylindrical core I6 of soft iron. Electrically secured with one end to the core I6, and secured with its lower end to a plunger I'I of soft iron, is a compression spring I8. Screwed to the bottom of the plunger Il is a rod I9 of conductive material carrying at its lower end a cylindrical igniting anode 'I, which in the position shown contacts with the mercury 3. A tube 20 of insulating material surrounds the rod I9 and protects same against the discharge. l

Supported by tube I4 is a metallic cylindrical screen 22 with closed top 3,3, the screen extending downwards to protect .the seal 23 from the discharge, and carrying a metal tube 2I forguid; ing rod I9 and tube 2U and extending through the slot 39. Thus plunger I'I, rod I9, tube 20, and anode 'I form a unit which may be moved vertically within tube 2I to lift anode 'I from the mercury and thus produce an auxiliary discharge between anode 'I and the cathode mercury 3. To produce this movement an actuating coil 24 surrounds the projecting portion 4U and is supported from terminal II.

Surrounding the rectier tube is a cooling jacket 26 divided into two chambers A and B by a ilange 25 of good heat-conducting material secured to member I. Upon inserting the rectifler tube into the jacket 26 the flange 25, with the aid of a suitable gasket 45, forms a liquidtight joint at 30, whereas a stud 2l extending through the bottom of the jacket 26 serves to hold the tube in place and as a cathode connection.

By arranging the chambers A and B adjacent and separating same by the member 25, a considerable portion of the heat energy transmitted to the insulating liquid 42 is conducted away by the circulatory liquid 4I, thereby insuringv a substantially lower temperature of the glass portion 2.

The top of jacket 26 is closed by a snugly-tting plate 30 of insulating material carrying a terminal connected through a conductor 36 to the main anode terminal I0, and a terminal 31 connected through coil 24 to the terminal II and to the anode 1. A safety valve 32 disposed in plate 30 serves to relieve any pressure which may be developed within chamber A, and a pete cock 3| serves to draw 01T the oil.

Such a construction makes it very simple to assemble the rectier inthe jacket 26. By making the diameter of jacket 26 of sufficient size it can be detached from the rectier in a single operation by loosening the stud 21.

Chamber B is provided with an inlet connection 28 and an outlet connection 29 for the flow of a. suitable circulating medium 4I, for instance water.

Chamber A is lled to a level at least above the top of the portion with a cooling insulating medium 42, which is in its liquid state when the rectifier is at its normal operating temperature.V

As a rule the temperature ofthe the metal portion is substantially at Ordinary temperatures.

The best operating conditions can be obtained preferably by maintaining the metal member I substantially at the temperature of the atmosphere by means of the circulating medium 4I, and by maintaining the glass part at a temperature which is sufficiently low to protect the glass portion 2 from excessive heat, but which is sufficiently above the temperature of the metal portion I to prevent mercury deposits upon the upper portion of the envelope.

These temperature conditions can be obtained by altering the radiating surface ofthe jacket of chamber A and by varying the circulating speed of medium 4I in vv.the chamber B. In this manner the glass portion I lis preferably given a temperature at least 40C. higher than the metal portion I.

If the glass portion 2 were cooled only by the surrounding air, as is generally the case, the portion of the glass portion in the vicinity of the seal 23, as well as the upper portion thereof, would be heated to a high temperature, whereas the intermediate portion would be very cold, and as a result a mercury deposit on this intermediate portion might bring about diculties during the operation. The use of the oil bath according to the invention overcomes these difficulties, as all portions of the envelope surrounded by the oil are maintained at a uniform temperature and at the proper degree.

It will be noted that the seal 23, as well as the support leads for the anodes 5 and 'I, and at least the upper part of anode 5, are surrounded by the chamber A; this giving very favorable results.. Furthermore, it will be noted that the component members of the assembly, including coil 24 and glass portion I, are adequately protected, the device is readily assembled and has asubstantially cylindrical shape.

While I have described my invention in connection with specific applications and examples, I do not wish to be limited thereto, but desire theappended claims to be construed as broadly as permissible in View of the prior art.

What I claim is:-

l. A single-phase mercury-vapor rectifier comprising an envelope having a metal portion and a glass portion hermetically sealed together to form a metal-to-glass seal, said metal portion serving as a condensation vessel and as a main discharge vessel, a mercury cathode within said metal portion, an anode within said envelope, a current supply conductor for said anode passing through said glass portion, means to maintain said metal portion at a predetermined temperature, and means to maintain all points of said glass portion and said metal-to-glass seal at a substantially uniform temperature which is higher than the temperature of said metal portion,

2. A single-phase mercury-vapor rectifier com- I prising an envelope having a cup-shaped metal portion and a glass portion hermetically sealed together to form a metal-to-glass seal, a mercury-cathode within said metal portion, and a main anode partly closing the open end of said cup-shaped metal portion to form therewith the discharge space of the tube, said metal portion also serving as a condensation chamber, a supply conductor for said anode hermetically sealedin said glass portion, and means to maintain all pointsof said glass portion and said metal-toglass seal at a. substantially uniform temperatures wh'iitlhvis.A highert than` the temperature of `said meterportion..` v i 3. -A'single-phase mercury-vapor rectifier comprising a cup-shaped metal portion serving as a Y condensation vessel and as a main discharge vesselwand` a vitreous portion fused` tosaid metal.

portion to form a metal-to-glassseal, a mercury.

fected on the surface thereof, and means for. maintainingall'v points of said Vvitreous portion` andsaid metal-to-glass seal` at a substantially uniformutemperaturel above Athe temperature at which'. there would be condensation `of mercury vaporiand .below the temperature at which said vitreous portion and seal Would be deleteriously affected.` i i .i i. i

4:1 Asingle-phase mercury-vapor rectier comprsing'an envelope having a cup-shaped metal bottom portion and a vitreous `portieri hermeti- -ycallysealed together to form a metal-to-glass s'ealia` mercury cathode Within said metaLportion, said metal portion serving as a condensation vessel. and as a main discharge vessel, a`

main anode and anauxiliary igniting anode with-- afin said envelope, current supply conductors for said anodeand passing through said vitreous porrounding said vitreous portion and said metalto-glass seal, a circulating cooling liquid within said rst chamber and in contact with said member, and a cooling substance within said second chamber and in contact with said member, said substance being in its liquid state during operation of the rectiiier. i

5. A single-phase mercury-vapor rectifier comprising an envelope having a metal portion and a glass portion hermetically sealed together to form a metal-to-glass seal, said metal portion serving as a condensation vessel and as a main discharge vessel, a mercury cathode within said metal portion, an anode Within said envelope, a current supply conductor for said anode passing through said glass portion, a cooling jacket surrounding said metal portion and adapted to receive a circulating cooling liquid, a secondcooling jacket surrounding said glass portion and said metal-toglass seal and an insulating substance within said second jacket, said substance being in its liquid state at the operating temperature of the rectier.

6. A single-phase mercury-vapor rectier comprising an envelope having a metal portion and a glass portion hermetically sealed together to form a metal-to-glass seal, said metal portion serving as a condensation vessel and as a main discharge vessel, a mercury cathodewithin said metal portion, an anode within said envelope, a current supply conductor for said anode passing through said glass portion, a cooling jacket surrounding said metal portion and adapted to receive a circulating cooling liquid, a second coo-ling jacket adjacent to said rst jacket and surrounding said glass portion and said metal-toglass seal, an insulating substance within said second jacket, said substance being in its liquid state at the operatingtemperature 1of the rectifier; and a member of` good heat-conducting material forming `a partition commonto both jackets..

7. A single-phase mercury-vapor rectifier comprising an envelopehaving a metalportion and a` glass portion hermetically sealed together to' form a metal-to-glass seal, said metal portion serving as a. condensation vessel and as a main discharge vessel, a mercury cathode within said" metal portion; an anode within said envelope, a'

current supply conductor for said anode passing through said glass'portion, a substantially cylinV drical closed cooling jacket surrounding said envelope,a member of good heat-conducting material separating said jacket into two chambers, aV circulating cooling medium within theichamber adjacent the metal portion, an insulating substance within the other chamber and adjai cent said glass portion and said metal-to-glass seal, said substance being in its liquid statev at the normaloperating temperatureV of therec-H tier.

8. LA single-phase mercury-vapor rectiiier comprising an envelope having a metal portion and a glass portion hermetically sealed together to formfarmetal-to-glass seal, said metal portion serving as a `condensation vessel and as a'main discharge vessel, a mercury cathode within saidl metal portion; an anode within said envelope, `a

cooling jacket surrounding saidrnetal envelope,

a memberfoi good heat`-conducting `material sep- 4 arating saidfjacketinto two chambers, a circu# lating cooling liquid within the chamber adjacent the metal portion, an insulating substance within the other chamber and adjacent said glassportion and said metal-to-glass seal, said substance being in its liquidstate at the normal op`- erating temperature of the rectifier, said member supporting said envelope from said jacket.

9. A single-phasemercury-vapor rectifier comprising an envelope having a metal portion and a glass portion hermetically sealed together to form a metal-to-glass seal, said metal portion serving as a condensation vessel and as a main discharge vessel, a mercury cathode disposed in said metal portion, an anode within said envelope, a cooling jacket surrounding said envelope and havin-g two chambers, a circulating cooling liquid in the chamber surrounding said metal portion, and an insulating substance within the other chamber and adjacent said glass portion and said metal-to-glass seal, said substance being in its liquid state at the operating temperature of the rectier, said jacket having a cross section larger than that of the envelope to allow removal thereof.

10. A single-phase mercury-vapor rectiiier comprising an envelope having a metal portion and a glass portion hermetically sealed together to form a metal-to-glass seal, said metal portion serving as a condensation vessel and as a main discharge vessel, a mercury cathode disposed in said metal portion, an anode within said envelope, means to maintain said metal portion at a predetermined temperature, and means to maintain every point of said glass portion and said metalto-glass seal at a substantially uniform temperature at least 40 C. higher than the temperature of the metal portion, said means comprising a cooling jacket around said metal portion andadapted to receive a circulating cooling liquid, a second cooling jacket around said glass portion and said seal, and an insulating substance within said second jacket, said substance being in its liquid state at the operating temperature of the rectifier.

11. A single-phase mercury-vapor rectifier comprising an envelope having a metal portion and a. glass portion jointed together to form a hermetic seal, said metal portion serving as a condensation vessel and as a main discharge vessel, a mercury cathode disposed in said metal portion, a main anode and an auxiliary anode within said envelope, supports and leads for said anodes extending through said glass portion, a jacket surrounding said glass portion, said metalglass seal, supports, leads and at least part of said main anode being surrounded by said jacket, an insulating substance within said jacket and being in its liquid state during operation of the rectifier, and a second jacket surroundng said metal portion and adapted to receive a circulating cooling liquid.

12. A single-phase mercury-vapor rectifier comprising an envelope having a metal portion and a glass portion hermetically sealed together to form a metal-to-glass seal, said metal portion serving as a condensation vessel and as a main discharge vessel, a mercury cathode within said metal portion, a main anode and an auxiliary anode within said envelope, supply conductors for said anodes extending through said glass portion, means including an electromagnet disposed outside said envelope to move said auxiliary anode into and out of contact with said mercury cathode, a cooling jacket surrounding saidy metal portion and adapted to receive a circulating cooling liquid, a second cooling jacket surrounding saidl glass portion, said metal-to-glass seal, part of said main anode, said supply conductors, and said coil, and an insulating substance Within said second jacket, said substance being in its liquid state at the operating temperature of the rectifier.

13. A single-phase mercury-Vapor rectifier comprising an envelope having a cup-shaped metal bottom portion and a glass portion hermetically sealed thereto to form a metal-to-glass seal, said metal portion serving as a condensation vessel and as a main discharge vessel, a mercury cathode within said bottom portion, a main anode and an auxiliary igniting anode Within said envelope, supply conductors for said anodes extending through said glass portion, a substantially cylindrical metal jacket surrounding said envelope, a member of good heat-conducting material secured to said metal portion, said member forming a liquid-tight joint with said jacket and dividing same into a closed chamber surrounding said glass portion and said metal-toglass seal and a second chamber surrounding said metal portion, a circulating cooling liquid within said second chamber, a cooling substance Within said first chamber, and a valve for relieving the pressure in said first chamber, said substance being in its liquid state during operation of the rectifier.

JOHANNES GIJSBERTUS WILHELM MULDER. 

